Ultrasound is used for different reasons at different stages in pregnancy. In the first stage of
the pregnancy, usually before 14 weeks, ultrasound scanning is used to check whether the
foetus is alive and whether it is alone or one of twins or triplets.
By measuring the length of the foetus it is also possible to accurately determine when the
baby will be due.
Some major abnormalities can also be detected at this stage. At 11 to 14 weeks,
measurement of the thickness of the skin at the back of the neck (known as nuchal
translucency measurement) can be used to calculate the risk of the foetus having a
chromosome abnormality.
From 18 weeks onwards, it is possible to examine the foetus in more detail. Most organ
systems can be examined to ensure that the foetus appears to be developing normally. The
spine, skull, brain, heart, lungs, kidneys, arms and legs can all be seen. If the mother is
overweight, then the quality of the examination may be poor.
From 30 weeks onwards, ultrasound is often used to estimate how well the baby appears to
be growing. It is difficult to be precise about this but it is often useful if the woman has had
a small baby in the past or has a condition that may affect the baby's growth, such as pre-
eclampsia.
The bloodstream in the umbilical cord is also examined to see if it is functioning well enough
to transport sufficient oxygen and nutrition to the foetus.
It is also possible to check the position of the placenta to see whether it is lying normally or
if the placenta is lying abnormally close to the inside of the cervix (a condition known as
placenta praevia).
(http://www.netdoctor.co.uk/health_advice/examinations/ultrasoundpregnancy.htm#ixzz2jcOknsOY)
What can an ultrasound scan be used for?
An ultrasound scan can be used in several ways:
To check your baby's size. At the dating scan, this gives a better idea of how
many weeks pregnant you are. Your due date will be adjusted according to the
ultrasound measurements.
To check whether you're carrying more than one baby.
To detect most abnormalities.
To show the position of your baby and the placenta. For example, when the placenta
is low down in late pregnancy, a caesarean section may be advised.
To check that the baby is growing normally (this is particularly important if you're
carrying twins or you have had problems in this pregnancy or a previous pregnancy).
the pregnancy, usually before 14 weeks, ultrasound scanning is used to check whether the
foetus is alive and whether it is alone or one of twins or triplets.
By measuring the length of the foetus it is also possible to accurately determine when the
baby will be due.
Some major abnormalities can also be detected at this stage. At 11 to 14 weeks,
measurement of the thickness of the skin at the back of the neck (known as nuchal
translucency measurement) can be used to calculate the risk of the foetus having a
chromosome abnormality.
From 18 weeks onwards, it is possible to examine the foetus in more detail. Most organ
systems can be examined to ensure that the foetus appears to be developing normally. The
spine, skull, brain, heart, lungs, kidneys, arms and legs can all be seen. If the mother is
overweight, then the quality of the examination may be poor.
From 30 weeks onwards, ultrasound is often used to estimate how well the baby appears to
be growing. It is difficult to be precise about this but it is often useful if the woman has had
a small baby in the past or has a condition that may affect the baby's growth, such as pre-
eclampsia.
The bloodstream in the umbilical cord is also examined to see if it is functioning well enough
to transport sufficient oxygen and nutrition to the foetus.
It is also possible to check the position of the placenta to see whether it is lying normally or
if the placenta is lying abnormally close to the inside of the cervix (a condition known as
placenta praevia).
(http://www.netdoctor.co.uk/health_advice/examinations/ultrasoundpregnancy.htm#ixzz2jcOknsOY)
What can an ultrasound scan be used for?
An ultrasound scan can be used in several ways:
To check your baby's size. At the dating scan, this gives a better idea of how
many weeks pregnant you are. Your due date will be adjusted according to the
ultrasound measurements.
To check whether you're carrying more than one baby.
To detect most abnormalities.
To show the position of your baby and the placenta. For example, when the placenta
is low down in late pregnancy, a caesarean section may be advised.
To check that the baby is growing normally (this is particularly important if you're
carrying twins or you have had problems in this pregnancy or a previous pregnancy).
